Control apparatus and control method for image blur correction

Abstract

A control apparatus controls blur correction by a first correction unit configured to move an element included in a system, a second correction unit configured to move a sensor in a direction intersecting an axis, and a third correction unit configured to correct, by processing, a tilt component of blur occurring from shake of an imaging apparatus in an image. The control apparatus controls the first and second correction units using at least a first scheme and a second scheme. The third control unit is controlled so that strength of the blur correction of the tilt component by the third correction unit is higher when the first scheme is used for control than when the second scheme is used for control.

What is claimed is: 
     
         1 . A control apparatus for controlling blur correction by a first correction unit configured to change a direction of an axis of a system by moving an element included in the system, a second correction unit configured to move a sensor in a direction intersecting the axis, and a third correction unit configured to correct, by processing, a tilt component of blur occurring from shake of an imaging apparatus in an image generated by processing a signal output from the senor, the sensor being configured to capture an object image formed by light transmitted through the system, the control apparatus comprising one or more processors that execute a program stored in a memory and thereby function as:
 a determination unit configured to determine strength of the blur correction of the tilt component by the third correction unit;   a calculation unit configured to calculate a correction amount of the third correction unit based on the determined strength of the blur correction and an amount of shake of the imaging apparatus; and   a control unit configured to control the first correction unit and the second correction unit using a plurality of schemes including at least a first scheme and a second scheme,   wherein the determination unit is configured to, in a case where the control unit controls the first and second correction units using the first scheme, determine a first correction strength as the strength of the blur correction, and in a case where the control unit controls the first and second correction units using the second scheme, determine a second correction strength higher than the first correction strength as the strength of the blur correction.   
     
     
         2 . The control apparatus according to  claim 1 , wherein the first scheme has a higher effect than that of the second scheme in reducing blur in an area of the image where image height is high. 
     
     
         3 . The control apparatus according to  claim 1 ,
 wherein the first scheme is a scheme for moving the sensor in a same direction as a direction of movement of the object image with respect to the sensor due to the shake of the imaging apparatus, and   wherein the second scheme is a scheme for moving the sensor in a direction of reducing a movement of the object image with respect to the sensor due to the shake of the imaging apparatus.   
     
     
         4 . The control apparatus according to  claim 1 ,
 wherein the first scheme is a scheme for moving the element so that a position of the object image moves more than an amount of movement of the object image with respect to the sensor due to the shake of the imaging apparatus, and   wherein the second scheme is a scheme for moving the element so that the position of the object image moves less than the amount of movement of the object image with respect to the sensor due to the shake of the imaging apparatus.   
     
     
         5 . The control apparatus according to  claim 1 ,
 wherein the first scheme includes moving the element excessively relative to the shake of the imaging apparatus, and moving the sensor to cancel excessive movement of the element, and   wherein the second scheme includes moving the element and the sensor so that an amount of movement of the object image with respect to the sensor due to movement of the element and the amount of movement of the object image with respect to the sensor due to movement of the sensor are both smaller than the amount of movement of the object image with respect to the sensor due to the shake of the imaging apparatus.   
     
     
         6 . The control apparatus according to  claim 1 , wherein the control unit is configured to, in a case where the amount of shake is a first amount of shake, control the first and second correction units using the first scheme, and in a case where the amount of shake is a second amount of shake greater than the first amount of shake, control the first and second correction units using the second scheme. 
     
     
         7 . The control apparatus according to  claim 1 ,
 wherein the strength of the blur correction is changed by changing an upper limit value of a blur correction amount by the third correction unit, and   wherein the upper limit value of the blur correction amount by the third correction unit in a case where the first correction strength is set is lower than that of the blur correction amount by the third correction unit in a case where the second correction strength is set.   
     
     
         8 . The control apparatus according to  claim 1 , wherein the third correction unit is configured to correct blur by geometrically deforming the image using projective transformation. 
     
     
         9 . The control apparatus according to  claim 8 , wherein the third correction unit is configured to perform blur correction of a translational component, blur correction of a rotational component, and blur correction of the tilt component. 
     
     
         10 . The control apparatus according to  claim 1 ,
 wherein the first correction strength is zero, and   wherein in a case where the first and second correction units are controlled using the first scheme, the third correction unit does not correct the tilt component of the blur.   
     
     
         11 . The control apparatus according to  claim 1 ,
 wherein the determination unit is configured to determine gain of the blur correction by the third correction unit as the strength of the blur correction, and   wherein the calculation unit is configured to calculate the correction amount using the gain.   
     
     
         12 . The control apparatus according to  claim 1 , wherein the control unit is configured to control the first and second correction units using the plurality of schemes by outputting at least one of information about a correction ratio between the first and second correction units, a correction amount of the first correction unit, and a correction amount of the second correction unit to the first and second correction units. 
     
     
         13 . The control apparatus according to  claim 12 , wherein the information about the correction ratio includes at least either information indicating a correction ratio of the first correction unit determined based on the amount of shake of the imaging apparatus detected or information indicating a correction ratio of the second correction unit determined based on the amount of shake. 
     
     
         14 . The control apparatus according to  claim 12 , wherein the information about the correction ratio includes at least either information indicating a relationship between the amount of shake of the imaging apparatus and a correction ratio of the first correction unit or information indicating a relationship between the amount of shake and a correction ratio of the second correction unit. 
     
     
         15 . The control apparatus according to  claim 12 , wherein the information about the correction ratio is information about a correction ratio between the first, second, and third correction units. 
     
     
         16 . An imaging apparatus comprising:
 the control apparatus according to  claim 1 ;   the sensor; and   the second correction unit,   wherein the determination unit is configured to determine whether a lens apparatus mounted supports a coordination scheme where the first scheme and the second scheme are switched based on the amount of shake, and determine the strength of the blur correction based on a result of this determination.   
     
     
         17 . The imaging apparatus according to  claim 16 , wherein the determination unit is configured to, in a case where the lens apparatus mounted supports the coordination scheme, determine the strength of the blur correction based on the amount of shake of the imaging apparatus. 
     
     
         18 . The imaging apparatus according to  claim 16 , wherein the determination unit is configured to, in a case where the lens apparatus mounted does not support the coordination scheme, set the strength of the blur correction to a constant value regardless of the amount of shake of the imaging apparatus. 
     
     
         19 . A control method for controlling blur correction by a first correction unit configured to change a direction of an axis of an system by moving an element included in the system, a second correction unit configured to move a sensor in a direction intersecting the axis, and a third correction unit configured to correct, by processing, a tilt component of blur occurring from shake of an imaging apparatus in an image generated by processing a signal output from the senor, the sensor being configured to capture an object image formed by light transmitted through the system, the control method comprising:
 determining strength of the blur correction of the tilt component by the third correction unit;   calculating a correction amount of the third correction unit based on the determined strength of the blur correction and an amount of shake of the imaging apparatus; and   controlling the first correction unit, the second correction unit, and the third correction unit using a plurality of schemes including at least a first scheme and a second scheme,   wherein in a case where the first and second correction units are controlled using the first scheme, a first correction strength is determined as the strength of the blur correction, and in a case where the first and second correction units are controlled using the second scheme, a second correction strength higher than the first correction strength is determined as the strength of the blur correction.